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2019-11-18Merge tag 'v4.14.154' into v4.14/standard/baseBruce Ashfield
This is the 4.14.154 stable release # gpg: Signature made Tue 12 Nov 2019 01:19:09 PM EST # gpg: using RSA key 647F28654894E3BD457199BE38DBBDC86092693E # gpg: Can't check signature: No public key
2019-11-12kvm: mmu: ITLB_MULTIHIT mitigationPaolo Bonzini
commit b8e8c8303ff28c61046a4d0f6ea99aea609a7dc0 upstream. With some Intel processors, putting the same virtual address in the TLB as both a 4 KiB and 2 MiB page can confuse the instruction fetch unit and cause the processor to issue a machine check resulting in a CPU lockup. Unfortunately when EPT page tables use huge pages, it is possible for a malicious guest to cause this situation. Add a knob to mark huge pages as non-executable. When the nx_huge_pages parameter is enabled (and we are using EPT), all huge pages are marked as NX. If the guest attempts to execute in one of those pages, the page is broken down into 4K pages, which are then marked executable. This is not an issue for shadow paging (except nested EPT), because then the host is in control of TLB flushes and the problematic situation cannot happen. With nested EPT, again the nested guest can cause problems shadow and direct EPT is treated in the same way. [ tglx: Fixup default to auto and massage wording a bit ] Originally-by: Junaid Shahid <junaids@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/cpu: Add Tremont to the cpu vulnerability whitelistPawan Gupta
commit cad14885a8d32c1c0d8eaa7bf5c0152a22b6080e upstream. Add the new cpu family ATOM_TREMONT_D to the cpu vunerability whitelist. ATOM_TREMONT_D is not affected by X86_BUG_ITLB_MULTIHIT. ATOM_TREMONT_D might have mitigations against other issues as well, but only the ITLB multihit mitigation is confirmed at this point. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/bugs: Add ITLB_MULTIHIT bug infrastructureVineela Tummalapalli
commit db4d30fbb71b47e4ecb11c4efa5d8aad4b03dfae upstream. Some processors may incur a machine check error possibly resulting in an unrecoverable CPU lockup when an instruction fetch encounters a TLB multi-hit in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. The relevant erratum can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=205195 There are other processors affected for which the erratum does not fully disclose the impact. This issue affects both bare-metal x86 page tables and EPT. It can be mitigated by either eliminating the use of large pages or by using careful TLB invalidations when changing the page size in the page tables. Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which are mitigated against this issue. Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com> Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/speculation/taa: Fix printing of TAA_MSG_SMT on IBRS_ALL CPUsJosh Poimboeuf
commit 012206a822a8b6ac09125bfaa210a95b9eb8f1c1 upstream. For new IBRS_ALL CPUs, the Enhanced IBRS check at the beginning of cpu_bugs_smt_update() causes the function to return early, unintentionally skipping the MDS and TAA logic. This is not a problem for MDS, because there appears to be no overlap between IBRS_ALL and MDS-affected CPUs. So the MDS mitigation would be disabled and nothing would need to be done in this function anyway. But for TAA, the TAA_MSG_SMT string will never get printed on Cascade Lake and newer. The check is superfluous anyway: when 'spectre_v2_enabled' is SPECTRE_V2_IBRS_ENHANCED, 'spectre_v2_user' is always SPECTRE_V2_USER_NONE, and so the 'spectre_v2_user' switch statement handles it appropriately by doing nothing. So just remove the check. Fixes: 1b42f017415b ("x86/speculation/taa: Add mitigation for TSX Async Abort") Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Borislav Petkov <bp@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/tsx: Add config options to set tsx=on|off|autoMichal Hocko
commit db616173d787395787ecc93eef075fa975227b10 upstream. There is a general consensus that TSX usage is not largely spread while the history shows there is a non trivial space for side channel attacks possible. Therefore the tsx is disabled by default even on platforms that might have a safe implementation of TSX according to the current knowledge. This is a fair trade off to make. There are, however, workloads that really do benefit from using TSX and updating to a newer kernel with TSX disabled might introduce a noticeable regressions. This would be especially a problem for Linux distributions which will provide TAA mitigations. Introduce config options X86_INTEL_TSX_MODE_OFF, X86_INTEL_TSX_MODE_ON and X86_INTEL_TSX_MODE_AUTO to control the TSX feature. The config setting can be overridden by the tsx cmdline options. [ bp: Text cleanups from Josh. ] Suggested-by: Borislav Petkov <bpetkov@suse.de> Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/tsx: Add "auto" option to the tsx= cmdline parameterPawan Gupta
commit 7531a3596e3272d1f6841e0d601a614555dc6b65 upstream. Platforms which are not affected by X86_BUG_TAA may want the TSX feature enabled. Add "auto" option to the TSX cmdline parameter. When tsx=auto disable TSX when X86_BUG_TAA is present, otherwise enable TSX. More details on X86_BUG_TAA can be found here: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html [ bp: Extend the arg buffer to accommodate "auto\0". ] Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/speculation/taa: Add sysfs reporting for TSX Async AbortPawan Gupta
commit 6608b45ac5ecb56f9e171252229c39580cc85f0f upstream. Add the sysfs reporting file for TSX Async Abort. It exposes the vulnerability and the mitigation state similar to the existing files for the other hardware vulnerabilities. Sysfs file path is: /sys/devices/system/cpu/vulnerabilities/tsx_async_abort Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/speculation/taa: Add mitigation for TSX Async AbortPawan Gupta
commit 1b42f017415b46c317e71d41c34ec088417a1883 upstream. TSX Async Abort (TAA) is a side channel vulnerability to the internal buffers in some Intel processors similar to Microachitectural Data Sampling (MDS). In this case, certain loads may speculatively pass invalid data to dependent operations when an asynchronous abort condition is pending in a TSX transaction. This includes loads with no fault or assist condition. Such loads may speculatively expose stale data from the uarch data structures as in MDS. Scope of exposure is within the same-thread and cross-thread. This issue affects all current processors that support TSX, but do not have ARCH_CAP_TAA_NO (bit 8) set in MSR_IA32_ARCH_CAPABILITIES. On CPUs which have their IA32_ARCH_CAPABILITIES MSR bit MDS_NO=0, CPUID.MD_CLEAR=1 and the MDS mitigation is clearing the CPU buffers using VERW or L1D_FLUSH, there is no additional mitigation needed for TAA. On affected CPUs with MDS_NO=1 this issue can be mitigated by disabling the Transactional Synchronization Extensions (TSX) feature. A new MSR IA32_TSX_CTRL in future and current processors after a microcode update can be used to control the TSX feature. There are two bits in that MSR: * TSX_CTRL_RTM_DISABLE disables the TSX sub-feature Restricted Transactional Memory (RTM). * TSX_CTRL_CPUID_CLEAR clears the RTM enumeration in CPUID. The other TSX sub-feature, Hardware Lock Elision (HLE), is unconditionally disabled with updated microcode but still enumerated as present by CPUID(EAX=7).EBX{bit4}. The second mitigation approach is similar to MDS which is clearing the affected CPU buffers on return to user space and when entering a guest. Relevant microcode update is required for the mitigation to work. More details on this approach can be found here: https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/mds.html The TSX feature can be controlled by the "tsx" command line parameter. If it is force-enabled then "Clear CPU buffers" (MDS mitigation) is deployed. The effective mitigation state can be read from sysfs. [ bp: - massage + comments cleanup - s/TAA_MITIGATION_TSX_DISABLE/TAA_MITIGATION_TSX_DISABLED/g - Josh. - remove partial TAA mitigation in update_mds_branch_idle() - Josh. - s/tsx_async_abort_cmdline/tsx_async_abort_parse_cmdline/g ] Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/cpu: Add a "tsx=" cmdline option with TSX disabled by defaultPawan Gupta
commit 95c5824f75f3ba4c9e8e5a4b1a623c95390ac266 upstream. Add a kernel cmdline parameter "tsx" to control the Transactional Synchronization Extensions (TSX) feature. On CPUs that support TSX control, use "tsx=on|off" to enable or disable TSX. Not specifying this option is equivalent to "tsx=off". This is because on certain processors TSX may be used as a part of a speculative side channel attack. Carve out the TSX controlling functionality into a separate compilation unit because TSX is a CPU feature while the TSX async abort control machinery will go to cpu/bugs.c. [ bp: - Massage, shorten and clear the arg buffer. - Clarifications of the tsx= possible options - Josh. - Expand on TSX_CTRL availability - Pawan. ] Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12x86/cpu: Add a helper function x86_read_arch_cap_msr()Pawan Gupta
commit 286836a70433fb64131d2590f4bf512097c255e1 upstream. Add a helper function to read the IA32_ARCH_CAPABILITIES MSR. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-15Merge tag 'v4.14.141' into v4.14/standard/baseBruce Ashfield
This is the 4.14.141 stable release
2019-09-15Merge tag 'v4.14.137' into v4.14/standard/baseBruce Ashfield
This is the 4.14.137 stable release
2019-09-15Merge tag 'v4.14.135' into v4.14/standard/baseBruce Ashfield
This is the 4.14.135 stable release
2019-09-15Merge tag 'v4.14.132' into v4.14/standard/baseBruce Ashfield
This is the 4.14.132 stable release
2019-09-15Merge tag 'v4.14.129' into v4.14/standard/baseBruce Ashfield
This is the 4.14.129 stable release
2019-09-15Merge tag 'v4.14.128' into v4.14/standard/baseBruce Ashfield
This is the 4.14.128 stable release
2019-09-15Merge tag 'v4.14.123' into v4.14/standard/baseBruce Ashfield
This is the 4.14.123 stable release
2019-08-29x86/CPU/AMD: Clear RDRAND CPUID bit on AMD family 15h/16hTom Lendacky
commit c49a0a80137c7ca7d6ced4c812c9e07a949f6f24 upstream. There have been reports of RDRAND issues after resuming from suspend on some AMD family 15h and family 16h systems. This issue stems from a BIOS not performing the proper steps during resume to ensure RDRAND continues to function properly. RDRAND support is indicated by CPUID Fn00000001_ECX[30]. This bit can be reset by clearing MSR C001_1004[62]. Any software that checks for RDRAND support using CPUID, including the kernel, will believe that RDRAND is not supported. Update the CPU initialization to clear the RDRAND CPUID bit for any family 15h and 16h processor that supports RDRAND. If it is known that the family 15h or family 16h system does not have an RDRAND resume issue or that the system will not be placed in suspend, the "rdrand=force" kernel parameter can be used to stop the clearing of the RDRAND CPUID bit. Additionally, update the suspend and resume path to save and restore the MSR C001_1004 value to ensure that the RDRAND CPUID setting remains in place after resuming from suspend. Note, that clearing the RDRAND CPUID bit does not prevent a processor that normally supports the RDRAND instruction from executing it. So any code that determined the support based on family and model won't #UD. Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Cooper <andrew.cooper3@citrix.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Chen Yu <yu.c.chen@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: Kees Cook <keescook@chromium.org> Cc: "linux-doc@vger.kernel.org" <linux-doc@vger.kernel.org> Cc: "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: <stable@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "x86@kernel.org" <x86@kernel.org> Link: https://lkml.kernel.org/r/7543af91666f491547bd86cebb1e17c66824ab9f.1566229943.git.thomas.lendacky@amd.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06x86/speculation/swapgs: Exclude ATOMs from speculation through SWAPGSThomas Gleixner
commit f36cf386e3fec258a341d446915862eded3e13d8 upstream Intel provided the following information: On all current Atom processors, instructions that use a segment register value (e.g. a load or store) will not speculatively execute before the last writer of that segment retires. Thus they will not use a speculatively written segment value. That means on ATOMs there is no speculation through SWAPGS, so the SWAPGS entry paths can be excluded from the extra LFENCE if PTI is disabled. Create a separate bug flag for the through SWAPGS speculation and mark all out-of-order ATOMs and AMD/HYGON CPUs as not affected. The in-order ATOMs are excluded from the whole mitigation mess anyway. Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06x86/speculation: Enable Spectre v1 swapgs mitigationsJosh Poimboeuf
commit a2059825986a1c8143fd6698774fa9d83733bb11 upstream The previous commit added macro calls in the entry code which mitigate the Spectre v1 swapgs issue if the X86_FEATURE_FENCE_SWAPGS_* features are enabled. Enable those features where applicable. The mitigations may be disabled with "nospectre_v1" or "mitigations=off". There are different features which can affect the risk of attack: - When FSGSBASE is enabled, unprivileged users are able to place any value in GS, using the wrgsbase instruction. This means they can write a GS value which points to any value in kernel space, which can be useful with the following gadget in an interrupt/exception/NMI handler: if (coming from user space) swapgs mov %gs:<percpu_offset>, %reg1 // dependent load or store based on the value of %reg // for example: mov %(reg1), %reg2 If an interrupt is coming from user space, and the entry code speculatively skips the swapgs (due to user branch mistraining), it may speculatively execute the GS-based load and a subsequent dependent load or store, exposing the kernel data to an L1 side channel leak. Note that, on Intel, a similar attack exists in the above gadget when coming from kernel space, if the swapgs gets speculatively executed to switch back to the user GS. On AMD, this variant isn't possible because swapgs is serializing with respect to future GS-based accesses. NOTE: The FSGSBASE patch set hasn't been merged yet, so the above case doesn't exist quite yet. - When FSGSBASE is disabled, the issue is mitigated somewhat because unprivileged users must use prctl(ARCH_SET_GS) to set GS, which restricts GS values to user space addresses only. That means the gadget would need an additional step, since the target kernel address needs to be read from user space first. Something like: if (coming from user space) swapgs mov %gs:<percpu_offset>, %reg1 mov (%reg1), %reg2 // dependent load or store based on the value of %reg2 // for example: mov %(reg2), %reg3 It's difficult to audit for this gadget in all the handlers, so while there are no known instances of it, it's entirely possible that it exists somewhere (or could be introduced in the future). Without tooling to analyze all such code paths, consider it vulnerable. Effects of SMAP on the !FSGSBASE case: - If SMAP is enabled, and the CPU reports RDCL_NO (i.e., not susceptible to Meltdown), the kernel is prevented from speculatively reading user space memory, even L1 cached values. This effectively disables the !FSGSBASE attack vector. - If SMAP is enabled, but the CPU *is* susceptible to Meltdown, SMAP still prevents the kernel from speculatively reading user space memory. But it does *not* prevent the kernel from reading the user value from L1, if it has already been cached. This is probably only a small hurdle for an attacker to overcome. Thanks to Dave Hansen for contributing the speculative_smap() function. Thanks to Andrew Cooper for providing the inside scoop on whether swapgs is serializing on AMD. [ tglx: Fixed the USER fence decision and polished the comment as suggested by Dave Hansen ] Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06x86/cpufeatures: Combine word 11 and 12 into a new scattered features wordFenghua Yu
commit acec0ce081de0c36459eea91647faf99296445a3 upstream It's a waste for the four X86_FEATURE_CQM_* feature bits to occupy two whole feature bits words. To better utilize feature words, re-define word 11 to host scattered features and move the four X86_FEATURE_CQM_* features into Linux defined word 11. More scattered features can be added in word 11 in the future. Rename leaf 11 in cpuid_leafs to CPUID_LNX_4 to reflect it's a Linux-defined leaf. Rename leaf 12 as CPUID_DUMMY which will be replaced by a meaningful name in the next patch when CPUID.7.1:EAX occupies world 12. Maximum number of RMID and cache occupancy scale are retrieved from CPUID.0xf.1 after scattered CQM features are enumerated. Carve out the code into a separate function. KVM doesn't support resctrl now. So it's safe to move the X86_FEATURE_CQM_* features to scattered features word 11 for KVM. Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Aaron Lewis <aaronlewis@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Babu Moger <babu.moger@amd.com> Cc: "Chang S. Bae" <chang.seok.bae@intel.com> Cc: "Sean J Christopherson" <sean.j.christopherson@intel.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Juergen Gross <jgross@suse.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: kvm ML <kvm@vger.kernel.org> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Nadav Amit <namit@vmware.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pavel Tatashin <pasha.tatashin@oracle.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: "Radim Krčmář" <rkrcmar@redhat.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Ravi V Shankar <ravi.v.shankar@intel.com> Cc: Sherry Hurwitz <sherry.hurwitz@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Lendacky <Thomas.Lendacky@amd.com> Cc: x86 <x86@kernel.org> Link: https://lkml.kernel.org/r/1560794416-217638-2-git-send-email-fenghua.yu@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-06x86/cpufeatures: Carve out CQM features retrievalBorislav Petkov
commit 45fc56e629caa451467e7664fbd4c797c434a6c4 upstream ... into a separate function for better readability. Split out from a patch from Fenghua Yu <fenghua.yu@intel.com> to keep the mechanical, sole code movement separate for easy review. No functional changes. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: x86@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31x86/speculation/mds: Apply more accurate check on hypervisor platformZhenzhong Duan
commit 517c3ba00916383af6411aec99442c307c23f684 upstream. X86_HYPER_NATIVE isn't accurate for checking if running on native platform, e.g. CONFIG_HYPERVISOR_GUEST isn't set or "nopv" is enabled. Checking the CPU feature bit X86_FEATURE_HYPERVISOR to determine if it's running on native platform is more accurate. This still doesn't cover the platforms on which X86_FEATURE_HYPERVISOR is unsupported, e.g. VMware, but there is nothing which can be done about this scenario. Fixes: 8a4b06d391b0 ("x86/speculation/mds: Add sysfs reporting for MDS") Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1564022349-17338-1-git-send-email-zhenzhong.duan@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-31x86/build: Add 'set -e' to mkcapflags.sh to delete broken capflags.cMasahiro Yamada
[ Upstream commit bc53d3d777f81385c1bb08b07bd1c06450ecc2c1 ] Without 'set -e', shell scripts continue running even after any error occurs. The missed 'set -e' is a typical bug in shell scripting. For example, when a disk space shortage occurs while this script is running, it actually ends up with generating a truncated capflags.c. Yet, mkcapflags.sh continues running and exits with 0. So, the build system assumes it has succeeded. It will not be re-generated in the next invocation of Make since its timestamp is newer than that of any of the source files. Add 'set -e' so that any error in this script is caught and propagated to the build system. Since 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"), make automatically deletes the target on any failure. So, the broken capflags.c will be deleted automatically. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/20190625072622.17679-1-yamada.masahiro@socionext.com Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-03x86/microcode: Fix the microcode load on CPU hotplug for realThomas Gleixner
commit 5423f5ce5ca410b3646f355279e4e937d452e622 upstream. A recent change moved the microcode loader hotplug callback into the early startup phase which is running with interrupts disabled. It missed that the callbacks invoke sysfs functions which might sleep causing nice 'might sleep' splats with proper debugging enabled. Split the callbacks and only load the microcode in the early startup phase and move the sysfs handling back into the later threaded and preemptible bringup phase where it was before. Fixes: 78f4e932f776 ("x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: stable@vger.kernel.org Cc: x86-ml <x86@kernel.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1906182228350.1766@nanos.tec.linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-07-03x86/speculation: Allow guests to use SSBD even if host does notAlejandro Jimenez
commit c1f7fec1eb6a2c86d01bc22afce772c743451d88 upstream. The bits set in x86_spec_ctrl_mask are used to calculate the guest's value of SPEC_CTRL that is written to the MSR before VMENTRY, and control which mitigations the guest can enable. In the case of SSBD, unless the host has enabled SSBD always on mode (by passing "spec_store_bypass_disable=on" in the kernel parameters), the SSBD bit is not set in the mask and the guest can not properly enable the SSBD always on mitigation mode. This has been confirmed by running the SSBD PoC on a guest using the SSBD always on mitigation mode (booted with kernel parameter "spec_store_bypass_disable=on"), and verifying that the guest is vulnerable unless the host is also using SSBD always on mode. In addition, the guest OS incorrectly reports the SSB vulnerability as mitigated. Always set the SSBD bit in x86_spec_ctrl_mask when the host CPU supports it, allowing the guest to use SSBD whether or not the host has chosen to enable the mitigation in any of its modes. Fixes: be6fcb5478e9 ("x86/bugs: Rework spec_ctrl base and mask logic") Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Mark Kanda <mark.kanda@oracle.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Cc: bp@alien8.de Cc: rkrcmar@redhat.com Cc: kvm@vger.kernel.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/1560187210-11054-1-git-send-email-alejandro.j.jimenez@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-22x86/CPU/AMD: Don't force the CPB cap when running under a hypervisorFrank van der Linden
[ Upstream commit 2ac44ab608705948564791ce1d15d43ba81a1e38 ] For F17h AMD CPUs, the CPB capability ('Core Performance Boost') is forcibly set, because some versions of that chip incorrectly report that they do not have it. However, a hypervisor may filter out the CPB capability, for good reasons. For example, KVM currently does not emulate setting the CPB bit in MSR_K7_HWCR, and unchecked MSR access errors will be thrown when trying to set it as a guest: unchecked MSR access error: WRMSR to 0xc0010015 (tried to write 0x0000000001000011) at rIP: 0xffffffff890638f4 (native_write_msr+0x4/0x20) Call Trace: boost_set_msr+0x50/0x80 [acpi_cpufreq] cpuhp_invoke_callback+0x86/0x560 sort_range+0x20/0x20 cpuhp_thread_fun+0xb0/0x110 smpboot_thread_fn+0xef/0x160 kthread+0x113/0x130 kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x35/0x40 To avoid this issue, don't forcibly set the CPB capability for a CPU when running under a hypervisor. Signed-off-by: Frank van der Linden <fllinden@amazon.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@alien8.de Cc: jiaxun.yang@flygoat.com Fixes: 0237199186e7 ("x86/CPU/AMD: Set the CPB bit unconditionally on F17h") Link: http://lkml.kernel.org/r/20190522221745.GA15789@dev-dsk-fllinden-2c-c1893d73.us-west-2.amazon.com [ Minor edits to the changelog. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-06-19x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callbackBorislav Petkov
commit 78f4e932f7760d965fb1569025d1576ab77557c5 upstream. Adric Blake reported the following warning during suspend-resume: Enabling non-boot CPUs ... x86: Booting SMP configuration: smpboot: Booting Node 0 Processor 1 APIC 0x2 unchecked MSR access error: WRMSR to 0x10f (tried to write 0x0000000000000000) \ at rIP: 0xffffffff8d267924 (native_write_msr+0x4/0x20) Call Trace: intel_set_tfa intel_pmu_cpu_starting ? x86_pmu_dead_cpu x86_pmu_starting_cpu cpuhp_invoke_callback ? _raw_spin_lock_irqsave notify_cpu_starting start_secondary secondary_startup_64 microcode: sig=0x806ea, pf=0x80, revision=0x96 microcode: updated to revision 0xb4, date = 2019-04-01 CPU1 is up The MSR in question is MSR_TFA_RTM_FORCE_ABORT and that MSR is emulated by microcode. The log above shows that the microcode loader callback happens after the PMU restoration, leading to the conjecture that because the microcode hasn't been updated yet, that MSR is not present yet, leading to the #GP. Add a microcode loader-specific hotplug vector which comes before the PERF vectors and thus executes earlier and makes sure the MSR is present. Fixes: 400816f60c54 ("perf/x86/intel: Implement support for TSX Force Abort") Reported-by: Adric Blake <promarbler14@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@vger.kernel.org> Cc: x86@kernel.org Link: https://bugzilla.kernel.org/show_bug.cgi?id=203637 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-31x86/mce: Fix machine_check_poll() tests for error typesTony Luck
[ Upstream commit f19501aa07f18268ab14f458b51c1c6b7f72a134 ] There has been a lurking "TBD" in the machine check poll routine ever since it was first split out from the machine check handler. The potential issue is that the poll routine may have just begun a read from the STATUS register in a machine check bank when the hardware logs an error in that bank and signals a machine check. That race used to be pretty small back when machine checks were broadcast, but the addition of local machine check means that the poll code could continue running and clear the error from the bank before the local machine check handler on another CPU gets around to reading it. Fix the code to be sure to only process errors that need to be processed in the poll code, leaving other logged errors alone for the machine check handler to find and process. [ bp: Massage a bit and flip the "== 0" check to the usual !(..) test. ] Fixes: b79109c3bbcf ("x86, mce: separate correct machine check poller and fatal exception handler") Fixes: ed7290d0ee8f ("x86, mce: implement new status bits") Reported-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Ashok Raj <ashok.raj@intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86-ml <x86@kernel.org> Cc: Yazen Ghannam <Yazen.Ghannam@amd.com> Link: https://lkml.kernel.org/r/20190312170938.GA23035@agluck-desk Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-31x86/microcode: Fix the ancient deprecated microcode loading methodBorislav Petkov
[ Upstream commit 24613a04ad1c0588c10f4b5403ca60a73d164051 ] Commit 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present") added the new define UCODE_NEW to denote that an update should happen only when newer microcode (than installed on the system) has been found. But it missed adjusting that for the old /dev/cpu/microcode loading interface. Fix it. Fixes: 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present") Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Jann Horn <jannh@google.com> Link: https://lkml.kernel.org/r/20190405133010.24249-3-bp@alien8.de Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-05-21Merge tag 'v4.14.119' into v4.14/standard/baseBruce Ashfield
This is the 4.14.119 stable release
2019-05-21Merge tag 'v4.14.117' into v4.14/standard/baseBruce Ashfield
This is the 4.14.117 stable release
2019-05-21Merge tag 'v4.14.114' into v4.14/standard/baseBruce Ashfield
This is the 4.14.114 stable release
2019-05-21Merge tag 'v4.14.113' into v4.14/standard/baseBruce Ashfield
This is the 4.14.113 stable release
2019-05-21Merge tag 'v4.14.106' into v4.14/standard/baseBruce Ashfield
This is the 4.14.106 stable release
2019-05-17Merge tag 'v4.14.99' into v4.14/standard/baseBruce Ashfield
This is the 4.14.99 stable release
2019-05-14x86/speculation/mds: Add 'mitigations=' support for MDSJosh Poimboeuf
commit 5c14068f87d04adc73ba3f41c2a303d3c3d1fa12 upstream Add MDS to the new 'mitigations=' cmdline option. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation: Support 'mitigations=' cmdline optionJosh Poimboeuf
commit d68be4c4d31295ff6ae34a8ddfaa4c1a8ff42812 upstream Configure x86 runtime CPU speculation bug mitigations in accordance with the 'mitigations=' cmdline option. This affects Meltdown, Spectre v2, Speculative Store Bypass, and L1TF. The default behavior is unchanged. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Jiri Kosina <jkosina@suse.cz> (on x86) Reviewed-by: Jiri Kosina <jkosina@suse.cz> Cc: Borislav Petkov <bp@alien8.de> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jon Masters <jcm@redhat.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: linux-s390@vger.kernel.org Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: linux-arch@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tyler Hicks <tyhicks@canonical.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Price <steven.price@arm.com> Cc: Phil Auld <pauld@redhat.com> Link: https://lkml.kernel.org/r/6616d0ae169308516cfdf5216bedd169f8a8291b.1555085500.git.jpoimboe@redhat.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations offKonrad Rzeszutek Wilk
commit e2c3c94788b08891dcf3dbe608f9880523ecd71b upstream This code is only for CPUs which are affected by MSBDS, but are *not* affected by the other two MDS issues. For such CPUs, enabling the mds_idle_clear mitigation is enough to mitigate SMT. However if user boots with 'mds=off' and still has SMT enabled, we should not report that SMT is mitigated: $cat /sys//devices/system/cpu/vulnerabilities/mds Vulnerable; SMT mitigated But rather: Vulnerable; SMT vulnerable Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20190412215118.294906495@localhost.localdomain Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Fix commentBoris Ostrovsky
commit cae5ec342645746d617dd420d206e1588d47768a upstream s/L1TF/MDS/ Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add SMT warning messageJosh Poimboeuf
commit 39226ef02bfb43248b7db12a4fdccb39d95318e3 upstream MDS is vulnerable with SMT. Make that clear with a one-time printk whenever SMT first gets enabled. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation: Move arch_smt_update() call to after mitigation decisionsJosh Poimboeuf
commit 7c3658b20194a5b3209a143f63bc9c643c6a3ae2 upstream arch_smt_update() now has a dependency on both Spectre v2 and MDS mitigations. Move its initial call to after all the mitigation decisions have been made. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mds=full,nosmt cmdline optionJosh Poimboeuf
commit d71eb0ce109a124b0fa714832823b9452f2762cf upstream Add the mds=full,nosmt cmdline option. This is like mds=full, but with SMT disabled if the CPU is vulnerable. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tyler Hicks <tyhicks@canonical.com> Acked-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14Documentation: Move L1TF to separate directoryThomas Gleixner
commit 65fd4cb65b2dad97feb8330b6690445910b56d6a upstream Move L!TF to a separate directory so the MDS stuff can be added at the side. Otherwise the all hardware vulnerabilites have their own top level entry. Should have done that right away. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mitigation mode VMWERVThomas Gleixner
commit 22dd8365088b6403630b82423cf906491859b65e upstream In virtualized environments it can happen that the host has the microcode update which utilizes the VERW instruction to clear CPU buffers, but the hypervisor is not yet updated to expose the X86_FEATURE_MD_CLEAR CPUID bit to guests. Introduce an internal mitigation mode VMWERV which enables the invocation of the CPU buffer clearing even if X86_FEATURE_MD_CLEAR is not set. If the system has no updated microcode this results in a pointless execution of the VERW instruction wasting a few CPU cycles. If the microcode is updated, but not exposed to a guest then the CPU buffers will be cleared. That said: Virtual Machines Will Eventually Receive Vaccine Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add sysfs reporting for MDSThomas Gleixner
commit 8a4b06d391b0a42a373808979b5028f5c84d9c6a upstream Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Add mitigation control for MDSThomas Gleixner
commit bc1241700acd82ec69fde98c5763ce51086269f8 upstream Now that the mitigations are in place, add a command line parameter to control the mitigation, a mitigation selector function and a SMT update mechanism. This is the minimal straight forward initial implementation which just provides an always on/off mode. The command line parameter is: mds=[full|off] This is consistent with the existing mitigations for other speculative hardware vulnerabilities. The idle invocation is dynamically updated according to the SMT state of the system similar to the dynamic update of the STIBP mitigation. The idle mitigation is limited to CPUs which are only affected by MSBDS and not any other variant, because the other variants cannot be mitigated on SMT enabled systems. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/speculation/mds: Conditionally clear CPU buffers on idle entryThomas Gleixner
commit 07f07f55a29cb705e221eda7894dd67ab81ef343 upstream Add a static key which controls the invocation of the CPU buffer clear mechanism on idle entry. This is independent of other MDS mitigations because the idle entry invocation to mitigate the potential leakage due to store buffer repartitioning is only necessary on SMT systems. Add the actual invocations to the different halt/mwait variants which covers all usage sites. mwaitx is not patched as it's not available on Intel CPUs. The buffer clear is only invoked before entering the C-State to prevent that stale data from the idling CPU is spilled to the Hyper-Thread sibling after the Store buffer got repartitioned and all entries are available to the non idle sibling. When coming out of idle the store buffer is partitioned again so each sibling has half of it available. Now CPU which returned from idle could be speculatively exposed to contents of the sibling, but the buffers are flushed either on exit to user space or on VMENTER. When later on conditional buffer clearing is implemented on top of this, then there is no action required either because before returning to user space the context switch will set the condition flag which causes a flush on the return to user path. Note, that the buffer clearing on idle is only sensible on CPUs which are solely affected by MSBDS and not any other variant of MDS because the other MDS variants cannot be mitigated when SMT is enabled, so the buffer clearing on idle would be a window dressing exercise. This intentionally does not handle the case in the acpi/processor_idle driver which uses the legacy IO port interface for C-State transitions for two reasons: - The acpi/processor_idle driver was replaced by the intel_idle driver almost a decade ago. Anything Nehalem upwards supports it and defaults to that new driver. - The legacy IO port interface is likely to be used on older and therefore unaffected CPUs or on systems which do not receive microcode updates anymore, so there is no point in adding that. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-14x86/kvm/vmx: Add MDS protection when L1D Flush is not activeThomas Gleixner
commit 650b68a0622f933444a6d66936abb3103029413b upstream CPUs which are affected by L1TF and MDS mitigate MDS with the L1D Flush on VMENTER when updated microcode is installed. If a CPU is not affected by L1TF or if the L1D Flush is not in use, then MDS mitigation needs to be invoked explicitly. For these cases, follow the host mitigation state and invoke the MDS mitigation before VMENTER. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Frederic Weisbecker <frederic@kernel.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>